Wharfie

#7 Support the commands COPY and CMD

- Minor compatibility fixes
- Install routine in Makefile, which includes QEMU

[#1] Build as non-root user
- use qemu to make non-root build
- needed host tools during build of qemu: all local wharfie tools and qemu-img
- needed host tools when building w/ qemu: tar, python
- biggest limitations:
--- The size of the possible input and output is hardly limitted.
--- The maximum output size is always fully allocated on disk

[#10]
- Support building of toolchains in one run.
- fixed build abortion
- fixed double creation of output file for temporary targets

- check for the tool kpartx
- made build more verbose, and included the hash in its output

- fixed rpi bootstrategy
- support kpartx w/ loopback w/o support for sync open

- fixed download in wharfile
- made bs more portable

[#9] Support CODESYS with self-contained raspbian libraries

--info didn't work anymore. fixed that

strip whitespaces from make target name

added missing return statement for toolchains

[#8] experimental implementation of incremental/multi-level build.
Actually it seems as tar has still problems with it. I can't avoid that tar thinks that s.th. is renamed, even if it is not.
In my tests I found no problems, except the warning from tar until now. But I added it as a command line option anyway, to be safe.

By-the-way I fixed the handling of files in ADD a bit.
- URLs are supported now
- Implicite makerules don't interfer anymore with ADD

fixed install issues, which came up after splitting the script up into libraries

[#6] Support downloading files

[#4] abort on error

[#5] throw parse error on wrong commands

restructured the main python script into submodules (curently only makefile generation and wharfile actions)

Added MIT License text globally, so that it can be found more easily

- added copyright statements + licenses

- cleaned up examples for toolchains
- renamed toolchain examples to a new scheme

- allow multiple, space separated value of environment variables
- support additional packages, specified via ADDITIONAL_TOOLCHAIN_PACKAGES in toolchains

Create feature branch for ticket [#1]

enable SPI and I2C on Raspberry Pi by default

added rules for 64 bit support

Prepared for the use of fakechroot, which actually failed atm. as I found no way of using it w/o heavily influence the host installation. And doing that would make the whole effort of avoiding root access futil$
But, it cleaned up the make targets pretty much.